Immune Checkpoint Inhibitor-Associated Pericarditis.

Side effects of immune checkpoint inhibitors, termed immune-related adverse events, are relatively common, but immune checkpoint inhibitor-mediated cardiotoxicities are rare; however, they can be serious and potentially fatal. Pericarditis is an infrequent cardiac toxicity of immunotherapy and predisposing factors remain unknown. Here we report three patients with NSCLC who developed pericarditis during therapy with programmed death 1/programmed death ligand 1+/- CTLA-4 inhibitors. We review the clinical presentation of these three cases and histopathologic findings from autopsies from the first two patients and a pericardial sampling that has been obtained from a pericardial window procedure in the third patient who recovered from the pericarditis episode. We also discuss the potential mechanisms, as well as what is known about pericarditis secondary to immune-related adverse events.